Effect of Uridine-Diphosphate-Glucose on Liver Glucuronyl Transferase Activity in Normal and in Fasting Rats

Enzyme ◽  
1972 ◽  
Vol 14 (6) ◽  
pp. 366-371 ◽  
Author(s):  
L. Okolicsanyi ◽  
S. Scremin
Keyword(s):  
Transferase Activity ◽  
Uridine Diphosphate ◽  
Glucuronyl Transferase ◽  
Uridine Diphosphate Glucose ◽  
Diphosphate Glucose

Galactose-1-Phosphate Uridyl Transferases Activity in Hemolysates of Newborn Infants

PEDIATRICS ◽  
1967 ◽  
Vol 39 (2) ◽  
pp. 293-294
Author(s):  
WON G. NG ◽  
WILLIAM R. BERGHEN ◽  
GEORGE N. DONNELL ◽  
JOAN E. HODGMAN
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Newborn Infants ◽  
Nicotinamide Adenine ◽  
Necessary Condition ◽  
Transferase Activity ◽  
Uridine Diphosphate ◽  
Uridine Diphosphate Glucose ◽  
Diphosphate Glucose ◽  
Normal Adults

Kabacy, et al. have shown by the uridine diphosphate glucose (UDPG) consumption assay that galactose-1-phosphate uridyl transferase (transferase) activity in hemolysates of newborn infants is significantly lower than for normal adults. Recent studies of hemolysate UDPGalactose-4-epimerase (epimerase) in newborns have suggested the possibility that the results of Kabacy, et al. may have been influenced by regeneration of UDPG by the epimerase reaction. A necessary condition for assay of transferase by UDPG consumption is that epimerase activity be negligible. We now have shown that epimerase activity in hemolysates from newborn infants is markedly elevated and, in contrast to findings with normal adults, substantial epimerase activity is present in the absence of exogenous oxidized nicotinamide adenine dinucleotide (NAD).

scholarly journals Studies on glycogen synthesis in pigeon liver homogenates. Glycogen synthesis from glucose monophosphates and uridine diphosphate glucose

1967 ◽  
Vol 105 (2) ◽  
pp. 515-519 ◽  
Author(s):  
V. N. Nigam
Keyword(s):  
Time Course ◽  
Initial Rate ◽  
Glycogen Synthesis ◽  
Uridine Diphosphate ◽  
Cytoplasmic Fraction ◽  
Uridine Diphosphate Glucose ◽  
Diphosphate Glucose ◽  
Liver Homogenates ◽  
Pigeon Liver ◽  
Glycogen Formation

Comparative time-course studies of glycogen synthesis from glucose 6-phosphate, glucose 1-phosphate and UDP-glucose show that glucose 1-phosphate forms glycogen at an initial rate faster than that obtained with glucose 6-phosphate and UDP-glucose. After 5min. the rates from glucose monophosphates are considerably slower. 2,4-Dinitrophenol decreases glycogen synthesis from both glucose monophosphates, whereas arsenate and EDTA increase glycogen synthesis from glucose 1-phosphate and inhibit the reaction from glucose 6-phosphate, galactose and galactose 1-phosphate. Mitochondria-free pigeon liver cytoplasmic fraction forms less glycogen from glucose monophosphates than does the whole homogenate. 2-Deoxyglucose 6-phosphate inhibits glycogen synthesis from glucose monophosphates. Glycogen formation from UDP-glucose is relatively unaffected by dinitrophenol, by arsenate, by EDTA, by 2-deoxyglucose 6-phosphate and by the removal of mitochondria from the whole homogenate.

scholarly journals The activity of uridine diphosphate glucose–d-fructose 6-phosphate 2-glucosyltransferase in leaves

1967 ◽  
Vol 105 (3) ◽  
pp. 943-946 ◽  
Author(s):  
J. S. Hawker
Keyword(s):  
Sugar Cane ◽  
Sucrose Synthesis ◽  
Uridine Diphosphate ◽  
Leaf Extracts ◽  
Uridine Diphosphate Glucose ◽  
Rate Of Photosynthesis ◽  
Diphosphate Glucose ◽  
Sucrose Phosphate Synthetase ◽  
High Sucrose ◽  
Sucrose Phosphate

1. By using EDTA in reaction mixtures it was possible to determine the activity of sucrose phosphate synthetase in freshly prepared leaf extracts without the complications caused by sucrose phosphatase. 2. EDTA was found also to increase the activity of sucrose phosphate synthetase by as much as 100%. 3. High sucrose phosphate synthetase activities were found in leaf preparations in which sucrose phosphatase was inhibited by EDTA. By contrast with previous reports, the activities were sufficient to allow sucrose synthesis in leaves during photosynthesis to occur via sucrose phosphate. 4. Sugar-cane plants having different rates of photosynthesis also had different activities of sucrose phosphate synthetase in their leaves. 5. It is suggested that the activity of sucrose phosphate synthetase in leaves may play a role in the control of the rate of photosynthesis.

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